am I the only dummy missing an instruction? the game takes off w/o my input, moving and blasting away. surely I'm just OOTL w/ PDF gameplay, which I blame myself for
Klick into that textbox at the right in the lower part of the page. Then type (WSAD, Z for enter, just as written there)
Doom does that by default. The background of the main menu features actual gameplay from a bundled demo file.
You are using higher-dpi laptop, probably. Unless you zoom out, the page only fits on generic full displays.